Machine for casting hollow articles



Jan. 8, 1952 G. c. Kol-n.

MACHINE FOR CASTING HOLLOW ARTICLES 10 Sheets-Sheet l Original FiledOct. 24, 1947 George C. Hgh] BY ATTORNEY Jan. 8, 1952 G. c. Kol-u.

MACHINE FOR CASTING HOLLOW ARTICLES l0 Sheets-Sheet 2 Original FiledOct. 24, 1947 18a 0 WZ LIL f '/4 INVENTOR. George C fohl BY ATTORNEYJan- 8, 1952 G. c. Kol-l1. 2,581,418

MACHINE FOR CASTING HoLLow ARTICLES George C. Koh! BY @/w- ATTORNEY Jan.8, 1952 ,.G. c. KoHl. 2,581,418

MACHINE FOR CASTING HOLLOW ARTICLES Original Filed Ooi. 24, 1947 10-Sheets-Sheet 4 I -INVENTR I ATTORN EY Original Filed Oct.

Jan. 8, 1952 G. c. KoHL 2,581,418

MACHINE FOR CASTING HOLLOW ARTICLES 24, 1947 10 Sheet's-Sheet 5 /66jme/wm George C. Kohl Jan. 8, 1952 G. c. KoHL 2,581,418

MACHINE FOR CASTING HOLLOW ARTICLES Original Filed Oct. 24, 1947 lOSheets-Sheet 6 figa ZI INVENTOR ATTORNEY Jan 8, 1952 G. c. Kol-n.2,581,418

MACHINE FOR CASTING HOLLOW ARTICLES original Filed om. 24, 1947 1oSheets-sheet 7 foe 107 INVENTOR G C /f /12 BYPo/"ge o l I wd ATTORNEYJan. 8, 1952 c. c. Kol-n. C 2,581,418

MACHINE FOR CASTING HOLLOW ARTICLES @riginal Filed Oct. 24, 1947 1CSheets-Sheet 8 INVENTOR ATTORNE Jan- 8, 1952 G. C. Kom. 2,581,418

MACHINE FOR CASTING HOLLOW ARTICLES Original Filed Oct. 24, 1947 10Sheets-Sheet 9 Vern/br Timer INVENTOR,

E 'q 16.' @orge c /fO/I/ G BY Jan. 8, 1952 G. c. KoHl. 2,581,418

MACHINE FCR CASTING HoLLow ARTICLES original Filed oci. 24, 1947 1o'sheets-sheet 1o (l) r m Fig 17. E E 75ml [/apsed 77'me per Cycle :3Uefa? 'H e Sen/"g Molds-f4 T-Z H Gripper 750 'T13 F' l CEH/C/' 53 7"-4 1W Jws-/ T5 K l VIb/CZTOS 'F6 C /\^^^^l l 52de Cores 5E In 'F7 E WWgi52de cores I Y 52 Dow/Z T' D Side (W5 5 Oul T-Q A A A ,i Y Side Cores-T-10 B Side CoreS '\/\/V\/\/\/\/\/\/L l 51 UHT 'F11 J l K Chue E00 Tme n.Seconds Naser Sw/ch l Comp/ehm Sar Hess? Con Tacs Open Sole/voids Deenerg/Zed ATTORNEY Patented Jan. 8, 1952 i 2,581,418 MACHINE Fon CASTINGIIoLLow ARTICLES George C. Kohl, University Heights, Ohio, as-

signor to Aluminum Company ol' America,

Pittsburgh, Pa.,

a corporation of Pennsylvania Continuation o'f application Serial No.781,794, October 24, 1947. This application August 9,

1950, Serial No.

11 Claims. (C1. 22-57) This invention relates In general to the castingart and is more particularly concerned with the design and provision ofimproved casting mechanisms for,producing substantially tubulararticles, of which cup-shaped castings or pistons for internalcombustion engines, which require in their production an internal coreor patrix member or members in cooperative association with a moldmember or members, are exemplary. It is in the piston casting field thatthe invention is hereinafter described in specific detail. Thisapplication is a continuation of my co-pending application, Serial No.781,794, filed October 24, 1947, now abandoned.

Casting equipment in general for producing hollow or cup-shaped articlesmust of necessity provide some form of internal core structureassociated with a mold member to dene the article to be cast. Dependingupon any specific article to be produced by casting, the internal coreor patrix must cooperatively combine and function with a mold cavity ormatrix to impart the desired configuration to the article to be cast. Inthe case of a piston for internal combustion engines, or the like, theinternal core or patrix structure quite often becomes complicated in itsdesign because of widely varying forms of internal ribs, bosses, andother internal configuration or contour, and although the invention isnot limited to any particular cast article or object, it can be statedherein that solution of the problems presented in providing asatisfactory piston casting mechanism will serve equally well in manyvother types of casting equipment.

The casting mechanisms contemplated herein pertain in general topermanent molding apparatus as distinguished from green sand foundrypractice and equipment, and by permanent mold apparatus or mechanism ismeant that type of equipment which employs metal molds and metal cores,or similar permanent non-frangible materials, which lend themselves torepeated use in the duplication of accurately sized castings. It shouldalso be understood that the various novel features incorporated in thecasting mechanisms` of this invention may be so coordinated, integratedand employed to function automatically as by power means,semi-automatically, in which some of the operations are performed bypower and others manually, or entirely manually.

Certain inherent difficulties and disadvantages prevail in castingmechanisms as represented by their present state of development. Suchprevailing disadvantages represent real problems in the casting art andit is a general object of the I invention to alleviate, and for the mostpart,

eliminate these problems. For example, a specific problem which has beensatisfactorily solved by the mechanisms of this invention is that ofeliminating the prevailing tendency of a molten metal charge to stick oradhere to a mold matrix or patrix during solidication of the moltenmetal in the production of a cast article.

It is well known that many metals and alloys, and particularly the lowspeciflc gravity metals and alloys of aluminum and magnesium, exhibit asevere tendency to adhere to metal mold matrix and patrix surfacesduring solidiiication of a molten metal charge in a casting operation.Mold washes and other forms of plating and surface treatment have beeneffective to a degree in overcoming this situation, but it is stillrecognized that such mold and core treatments do not performsatisfactorily in all instances. Furthermore, mold washes and othersurface treatments must be renewed periodically and their greatest useand benefit seem to be derived/from their heat insulating values asdistinguished from any alleviation of the aforementioned stickingproblem.

The sticking tendency above referred to is greatly exaggerated in thecase of castings having re-entrant portions on their interior coredsurfaces. This is exemplified in the case of a piston in which theinterior wrist pin bosses project inwardly from the piston skirt and areformed during a casting operation by proled core members machined orotherwise formed to impart the desired interior configuration to thepiston. Since the wrist pin boss-forming or controlling cores arerelatively thin in cross section adjacent the bosses, and since suchcores must extend outwardly beyond the casting cavity in a mold to aposition where they may be freely manipulated by a mold operator, orpower means, considerable ilexing of the thin core sections is normallyexperienced which often results in unpredictable paths of movement ofthe cores during their removal from a finished casting: Any sticking ofthe core sections in contact with the solidifying metal castthereagainst adds to the diculty of extracting the cores, on completionof a casting operation, and subjects elements that should be otherwisenormally and freely removable to bending strains and stresses, as wellas to inaccurate movements, as measured in point of time and directionduring a casting cycle. This deleterious condition is most pronounced inpower operated ymolding apparatus wherein the entire cycle yo1'manipulating the mold and core members is automatically performed inproper timed sequence without reliance upon manual core extraction,which latter manual operation may be delayed or interrupted at any timeby an operator in the event one or more core sections require additionaltime te remove the same from a cast article within a complementary moldcavity.

. A further problem that is attributable to the sticking tendencyobserved at the time of removal of core sections, followingsolidification of metal cast thereagainst, is the gouging or cuttingaction which often occurs when relatively thin, flexible core membersare suddenly released at the instant the sticking tendency is overcome.This will be appreciated when it is considered that internal core orpatrix members normally incorporate relatively sharp profiled edges. andwhen a core so constructed is initially held through adherence to thesurface of a solidified casting and thereafter released in a stressedand fiexed condition, the resultant path of movement of the core sectioncould readily be in a path and direction to gouge or cut into arelatively soft internal surface of a newly solidified or embryoniccasting.

Economy in the operation of a casting mechanism is generally measurablein terms of the time consumed in carrying through a complete castingcycle that can be here defined, in its simplest form, as comprisingpouring a charge of molten metal into a mold, awaiting a xed interval oftime for freezing and solidification of the molten charge, exposing thesolidified casting, withdrawing the core or cores from the interior ofthe casting, removing the stripped casting, and reassemblying the moldand core mechanisms for a subsequent casting operation. To the elapsedtime of the casting cycle can be added the lost time resulting fromshut-down periods for repairs and maintenance, and in the case ofmanually, or semimanually operated mechanisms, the further time factorrepresented by operator fatigue and timeconsuming manual operations mustbe taken into consideration in a nal economy analysis of any particularcasting apparatus.

Except in the ingot casting art, where relatively large, solid and heavycastings are produced, manual removal of castings from molds has, forthe most part, been considered satisfactory.

In cases where the objects being cast are of a complicated design, suchas pistons for internal combustion engines, and require complicatedinternal core members, in combination with a mold matrix, to define thefinished product, manual removal of a cast piston from its mold and corestructures may offer considerable diiiiculty as a result of the tendencyof the internal cores to stick to the solidified casting charge.Furthermore, manual removal ofcastings in many cases, and in particularfrom molding mechanisms employing complicated internal core members,will normally entail and be accompanied by rough handling to free acasting from its internal core supporting structure.

Development of automatic and semi-automatic molding apparatus gives riseto an ideal situation for eliminating many of the time consumingoperations normally associated with casting apparatus, and as aparticular feature of the present invention, a mechanical core strippingdevice permits removing a casting in its embryonic state, followingsufficient solidiflcaticn to support the weight of the cast article, inwhich case the hot metal casting may be still quite soft, therebyeliminating rough handling on the part of an operator, as well ascontributing to a reduction in an operators time attending themechanism.

It is also well known to cool casting equipment by means of circulatingwater, or other cooling media, internally or in contact with exposedsurfaces of mold equipment, and it is also common practice todifferentially retard heat extraction from a casting cavity in a mold toinsure certain desirable metallurgical and casting characteristicsduring solidification and freezing of a casting charge of molten metalwithin the mold. For the most part temperature control of moldingequipment has been directed primarily to the temperature of the articlebeing cast, whether the temperature control technique or means forcarrying out the technique is applied in the form of a heat extractingcoolant, or selection and disposition of mold materials exhibitingdifferential heat conducting capacities.

The temperature control of a molding apparatus during a castingoperation normally exhibits its beneficial result in the final castobject or product. There is still a problem, however, associated withthe temperature at which the molding apparatus may be operated that doesnot necessarily involve either the casting technique or properties of afinished casting. This problem concerns the cooling or chilling of thecasting apparatus, or portions thereof, during its period of non-useafter each castingr cycle or between successive casting operations. Itwill be understood that any temperature control that is essential to theproduction of a sound casting and which is employed during the actualintroduction and solidiiication of a molten metal charge in a mold, isreadily distinguishable from that heat retained by the molding equipmentonce a finished casting had been removed therefrom.

The enumerated problems, and many others that will be apparent to thoseskilled in this art, have been satisfactorily solved by the castingequipment of the present invention, as will be hereinafter described inspecific detail.

It is an object of the present invention to provide an improved castingmechanism that incorporates in its construction positive means foraccurately guiding an internal core or patrix member during its removalfrom and entry into a mold cavity or matrix.

It is another object to provide a casting mechanism for producingcup-shaped articles in which a multipart core or patrix serves incooperative relationship with a mold to form a casting cavity, and inwhich the core parts are supported and positively guided during theirremoval from the entry into the mold to insure against faulty andunpredictable movement of the core parts relative to the mold andcasting cavity formed therein.

Another object is to provide an improved casting apparatus in which aninternal core or patrix member is employed with a mold member with meansassociated with the apparatus to relieve the tendency of the patrix toadhere to a casting produced in the apparatus.

A further object is to provide an improved casting apparatus in whichmeans is provided for vibrating an internal core member to insurefreeing the same from adherence with a molten metal charge castthereagainst.

It is an object of the invention to provide a casting apparatusincorporating an internal core or patrix cooling or chilling mechanismfor use between successive casting operations, or during non-useperiods.

A further object is to provide a casting mechanism that incorporates inits construction a positive means for removing articles cast therein.

Another object is to provide a casting mechanism in which articles casttherein are positively held or gripped during the step of stripping aninternal core therefrom.

A still further object is to provide a casting mechanism which isentirely automatic in its operation to assemble a mold and an internalcore structure in cooperative relationship to serve as a molten metalreceiving cavity, and thereafter function in proper timed sequence togrip a casting produced therein, withdraw a core, remove the casting andreturn the mechanism to cooperative relationship for a subsequentcasting operation.

Numerous other objects and advantages will become apparent to thoseskilled in this art on consideration of the following description, whenread in conjunction with the drawings attached hereto and forming a parthereof, in which:

Fig. 1 represents a rear elevational view of a casting mechanismincorporating the features of the invention in a coordinated assemblysuitable for the production of cast pistons, or the like;

Fig. 2 represents an end elevation of the mechanism viewed from theright of Fig. 1, with parts broken away to more clearly show the mode ofconstruction;

Fig. 3 represents a top plan view of the mechanism illustrated in Figs..1 and 2;

Fig. 4 represents a fragmentary elevational view, to enlarged scale andin partial section, taken along the line IV-IV of Fig. 2;

Fig. 5 represents a fragmentary plan view, to enlarged scale, takenalong the line V-V of Fig. 2;

Fig. 6 represents a sectional elevation taken along the line VI-VI ofFig. 5;

Fig. 7 represents a sectional elevation, to enlarged scale, taken alongthe line VII-VII of Fig. 3;

Fig. 8 represents a fragmentary plan view, to enlarged scale and inpartial section, taken along the line VIII- VIII of Fig. l;

Fig. 9 represents a fragmentary partial sectional elevation taken alongthe line IX-IX of Fig. 8, and illustrating relatively movable parts ofthe mechanism in a selected intermediate core stripping position;

Fig. l0 represents a fragmentary partial sectional elevation similar toFig. 9 and illustrating relatively movable parts of the mechanism inrelation to a later stage in the operation of the mechanism;

Fig. 11 represents a fragmentary sectional elevation taken along theline XI-XI of Fig.

Fig. 12 represents a fragmentary sectional elevation taken along theline XII- XII of Fig. 11;

Fig. 13 represents a fragmentary sectional elevation taken along theline XIII-XIII of Fig. 10;

Fig. 14 vrepresents a fragmentary plan view taken along the line XIV-XIVof Fig. 12;

Fig. 15 represents a diagrammatic illustration of an integrated powersystem for the mechanism;

Fig. 16 represents a Wiring diagram; and

Fig. 17 represents a chart illustrating a cycle of operation of themechanism.

`In general terms, the casting or molding mechanisms contemplated withinthe scope of the invention incorporate a mold or matrix which ismachined or otherwise formed to define the entire or a substantialportion of the exterior surface of the cast article to be produced. Acore or patrix member is associated with the mold and is adapted to betranslated into and out of the mold to define therewith the interiorsurface ofA the cast article. The core is so mounted and actuatedl thatits path of movement into and out of the mold is positively controlledin a manner to impart rectilinear movement which, on withdrawal, is awayfrom and outwardly of the interior surface of the cast article which ithas defined. This particular path of movement insures positive freeingof the core surface from contact with all newly cast surfaces defined byit in its casting position with respect to its complementary moldcavity. An angularly disposed guide member serving to support the coremember, and defining the path of movement of the core, serves as themeans for imparting the aforedescribed directional movement of the corewhich carries it way from and out of registry with all surfaces withwhich it was in contact during the casting operation. It will beobserved that the specific path of movement of the core will assist inovercoming any resultant damage to a newly cast surface in the eventthat the core, or any portion thereof, tends to initially stick oradhere and is thereafter violently released, since no portion of thecore coincides or registers with the initial dened surface of thecasting following movement of the core as defined in terms of a path ofmovement away from and outwardly of, or out of registry with, theinterior surface of the article being cast.

A further assurance against the sticking tendency between a core and themetal cast thereagainst is provided in the form of a vibratory meansassociated with the core for imparting a series of rapid impulses orblows to the core before any attempt is made to withdraw the same fromthe interior of a casting which it denes.

A further feature incorporated in the mechanisms contemplated within thescope of the invention pertains to a core chilling or cooling meansassociated with the core structure during the period in a casting cycleintermediate successive casting operations, or during a non-use period.The core chilling or cooling means cornprises in its essentials a spraynozzle positioned adjacent the core during the interval in point of timebetween successive casting operations and insures a metered volume ofcoolant directed on the core surface. This feature of the invention hasbeen successful in shortening the interva' of non-use between castingoperations, as well as accurately controlling the temperature of themolding apparatus to a degree that is refiected in alleviation of theadherence of the solidified molten metal to a core defining surface.

Coupled with the above listed features, the invention provides positivemeans for gripping and stripping a casting on completion of a castingoperation preparatory to a subsequent casting operation. The gripper andstripper comprises, in general, a pair of gripping elements or shoesprofiled to positively grasp a cast article on its exterior surfacefollowing exposure of the same by removal of the exterior defining mold,and while the cast `article is still supported upon an interior coremember. While thus grasped the internal core is Withdrawn and thecasting or cast article is thereafter transported within the grippingmeans to a new location Where it is deposited out of interference with asubsequent casting operation.

All of the above mechanical features, singly and/or in combination, areadapted to be manually or power operated, a control system,incorporating a timer mechanism, being provided for automatic poweroperation of the combined elements and instrumentalities in speciedtimed sequence and relation.

General arrangement A casting mechanism, selected for purposes ofdisclosing and describing one mode of practicing the invention, isillustrated in the form of a two mold piston casting machine. In thegeneral arrangment of the illustrated mechanism a main base member orframe I0, preferably constructed in the form of a hollow housing made ofcast iron, or the like, serves to support and house the various elementsand subassemblies of the molding mechanism. A molding plate I2,preferably a heavy wear-resistant steel plate, is removably secured tothe frame I within a depression (Fig. 1) in the upper surface of thesame, and two piston casting molds Il are suitably supported on the topsurface of plate I2. The molds may be of any suitable construction solong as they permit exposure of a casting following its solidification.For example, multipart molds, hingedly mounted for oscillatory movementaway from a cast article to expose the same, such as a book-type mold,or medially split molds, such as herein illustrated and comprising moldsections I6 and Il that are slidably assembled on the mold plate I2, arewithin the contemplation of the invention, it being essential that themold sections in assembled, molten metal receiving relationship presentor form a casting cavity that defines the exterior surface of the castarticle to be produced.

A core mechanism or system is mounted within the base I0 and below themolding plate I2. In the mechanism selected for purposes ofillustration, the core mechanism, identified in its entirety byreference numeral 50 (Fig. 9), incorporates two oppositely disposedinternal wrist pin boss-forming or side cores and a center core for eachpiston casting mold. Vibratory means i8 are also associated with one .ormore of the internal cores to assist in their removal from the interiorof a cast piston.

A gripper and conveyor means, generally identified at ISI), isreciprocally mounted with respect to the main base I for movement intogripping relationship with cast pistons, or the like, exposed byremoving the molds Il therefrom. The gripper |50 serves to grasp andsecurely hold the cast pistons while one or more of the internal coresare withdrawn therefrom, and serves the additional function of aconveyor to remove the cast pistons to a location out of interferencewith reassembly of the casting mechanism for a subsequent castingoperation.

A piston receiving chute 200 is mounted on a translatory frame formovement into and out of piston receiving position beneath the gripperand conveyor member |50 (Figs. l, 2, 3, l0 and 15). As will behereinafter explained in more detail, the chute 2M) is pivotally mountedon its translatory frame and is tilted to discharge pistons receivedtherein in proper timed sequence in the operation of the piston castingmechanism.

Combined with the chute 200 and its translatory frame is a coolant orcore chilling system. This system cooperates with the chute in itspiston receiving position (Fig. 10) to direct a coolant spray upon theinternal cores of the mechanism.

Although manual operation of the mechanism is contemplated within thescope of the invention, a power system is outlined in Fig. 15, and awiring diagram for complete automatic operation of the mechanism isillustrated in Fig. 16. The power system and automatic control for thesame will be taken up in detail hereinafter.

Mold and wrist :vin cores 'access to machining, or otherwise forming orshaping the casting cavity, sprues, gates and risers in the moldsections, and the abutting surfaces in plane I8 may be scored orotherwise provided with radial grooves 2I extending from the castingcavity to atomsphere to serve as a mold venting means. The gating system22 for each mold I4 may be of any suitable type, but in its preferredform a gating system similar to that described and claimed inApplication Serial No.

761,087 (Charles G. Jancura) iled July 15, 1947, now matured into PatentNo. 2,521,520, has been found highly satisfactory.

Molds I4 are equipped with laterally extending flanges 23 (Figs. 7 and8), which in combination with gibs 24, keeper bars 25 and keys 26 serveto slidably secure and align the mold sections I8 and I1 on the moldingplate I2. In order that ready replacement and substitution of molds I4may be accomplished, keeper bars 25 are provided with keyhole slots orapertures 21 through which retention bolts or cap screws 28 extend. Thebolt elements 28 threadingly engage in the gibs 24 which are suitablysecured to the plate I2, as by means of countersunk screws 29 (Fig. 8).By slackening off the cap screws 28, keeper bars 25 are slidable inendwise direction (Fig. 8) to register the keyhole slot enlargementswith the heads of members 28 to thereby permit removal of keeper bars25, as well as removal and substitution of mold sections as desired.

Each mold section I6 and Il is provided with means for reciprocating thesame into and out of molten metal receiving and finished castingexposure position. In the preferred and illustrated form of theinvention, fluid pressure operated cylinders 30 are suitably secured tothe upper surface of the main base Il) and are connected through theirconnecting rods 3| with the mold sections I6 and I1. In the case of theillustrated piston casting mechanism, cores for forming wrist pin boresare coordinated and combined with the mold opening and closingmechanism. In the preferred form (Fig. 8 and 9) mold sections I6 and I1are each provided with a pair of substantially Z-shaped brackets 32secured to an outer face of each mold section by means of studs 33 andwedge pins 34. Each pair of Z- brackets 32 constitutes a housing withinwhich a flanged cross head 35 is received. Each cross head 35 isconnected to the exposed end of a connecting rod 3 I, extending into thehousing formed by Z-brackets 32, by means of a lost motion connectioncomprising the threaded cap member 36 and pinned collar 3l, the latterbeing attached to the extreme outer end of each connecting rod 3I andreceived within a cavity 38 in each of the flanged cross heads 35. Thecross heads 35 are each connected, as by bolts or the like (Fig. 8), toflanged wrist pin cores 4I), mounted in suitably bushed aperturesthrough the mold sections I8 and i1, and each core 40 is proportionedvinits length to extend into the casting cavity in the mold to form itsintended wrist pin bore. By

:insane proper selection of thickness of collar 31, the aforementionedlost motion connection between connecting rods 3| and cores 48 isaccomplished.

A further lost motion connection 39 (Fig. 8) is provided between each ofthe cross heads 35 and associated mold sections I6 motion connectiontakes the form of a definite clearance, within the housings formed by Z-brackets 32, as represented by the diil'erence between the combinedthickness of the abutting and bolted flanges on each of the cross heads35 and cores 48 and the depth of each housing as measured under theinwardly turned or projecting flanges of Z-brackets 32. It wlll be seenthat `fluid pressure admitted to cylinders 38 to open the mold sections,as viewed in Fig. 8, will initially cause the connecting rods 3| to takeup the lost motion 38 between collars 31 and the underside of caps 36(Fig. 9) to loosen the wrist pin cores 48. Continued outward movement ofthe connecting rods 3| will cause cross heads 35 to take up the lostmotion 39 within the housings formed by Z-brackets 32 to sequentiallywithdraw the wrist pin cores 48 and separate the mold sections I6 and|1. It will be apparent that the clearance 38, between each-collar 31and the underside of cap 36, may be so proportioned with respect to theclearance 39, between the flange on each of the cross heads 35 andinwardly turned flan es on the Z-brackets 32, that outward movement ofthe connecting rods 3| will initially serve to loosen and slightlywithdraw the wrist pin cores 48, whereas continued movement willseparate the mold sections I6 and I1.

Internal core mechanism The internal core mechanism, 'as distinguishedfrom the wrist pin cores 48, has been generally identified hereinaboveby the reference numeral 58 (Fig. 9). Since the selected illustration ofmolding mechanism pertains to a piston casting machine, the internalcore structure is now described in terms of such a machine for castingpistons in which the unobstructed distance between the interiorlyprojecting wrist pin bosses is less than that distance occupied by theinternal core members employed to form the wrist pin bosses, if suchcore members were positioned back to back within the interior of a castpiston. With such a dimensional relationship as here described,

it would be impossible to withdraw a cast piston over two side coremembers positioned back to back in the plane of the central verticalaxis through the piston on completion of a casting operation.

Internal core mechanism-58 includes at least two oppositely disposedwrist pin boss-forming side cores and 52 and a central core member 53 incooperative association with each mold |4. In the apparatus selected forillustrating the invention, side cores 5| and 52 are identical insofaras manipulated is quite different because of the aforesaid dimensionalrelationship, or narrow width of the unobstructed distance between theinternal wrist pin bosses.

Each side core 5| is secured, as by machine screws or the like. at itslower end below the under surface of molding plate I2. to a tapered orwe .ige-shaped shoe element 54 Member 54 has a flat upper surface 55(Figs. 9 and 13), lower inclined surface 55 and laterally extendingflanges 51, the upper surfaces of which are parallel with and I1. Thislost 9 the depth of cavity 33 and I tion of shoe member 54,

the lower inclined surface 56. A complementary guide box is flxedlymounted on the underside of molding plate" I2 for receiving andsupporting member 54. The guide box comprises an upper section 58secured to the underside of plate I2, as by suitable cap screws. Section58 is of generally inverted U-shape in cross section, its downwardlydepending legs vor flanges 68 terminating von an inclined plane of thesame slope as the under surface of member 54, and the depending flanges68 are rabbeted at 82 to conform with the slope and thickness of lateralflanges 51 of member 54. Bottom plates (two in number) or retainerstrips 84 are\ ured tothe underside of depending flanges 6 and presentinclined surfaces 55 in supporting and bearing relationship with respectto the underside of member 54. I The plates 64 are centrally spaced fromeach other to provide clearance for a depending rib or tang 18,integrally formed on the underside of member 54 (Figs. 9, l0 and 13), aswell as permit upward extension of replaceable stop blocks 58, securedto the underside of each plate 64 and extending upwardly into positionto abut with depending webs forming integral lugs 69 with the rear endor edge of shoe member 54 (Figs. 9 and 10) It will be observed from thedescribed construcf and its complementary guide box, that relativemovement between the shoe 54 and its guide box will cause its attachedside core 5| to move inwardly towards the center of the piston (Fig. 9)in -a straight line path that is inclined downwardly and inwardlytowards. and on projection forms an acute angle with, the verticalcentral axis of the cast piston. To obtain this rectilinear movement ofa side core 5|, its shoe 54 is clevis and pin connected through themedium of the aforementioned lugs 69 to the end of connecting rod 1which extends outwardly from a power cylinder 12, pivotally secured at13 to the underside of the main base I8 (Figs. 1 and 8). It will also befully understood that normal clearances will be provided between theshoe 54 and its complementary guide box for free sliding relativemovement therebetween.

Each side core 52 fis likewise provided at its lower end beneath themolding plate I2 with a tapered oriwedge-shaped shoe member 88 rigidlysecured thereto. The shoe member 88 presents a flat upper surface 82(Figs. 9 and 12), lower inclined surface 84 and extending lateralflanges 85, the upper surfaces of which lateral flanges Aare parallelwith the inclined surface 84. zA complementary guide box advantage inFigs. 9, 10, l1, 12 and 14, is mounted on the upper or top surface of aplatform 86 located beneath the aforementioned molding plate I2. Theguide box for shoe 88, and its integrally attached core 52, comprises anupper section 88 of generally inverted U-shape in cross section, itsdownwardly depending legs or flanges 89 terminating on an inclined planeof thesame slope as the under surface 84 of the shoe 88. The dependingflanges 89 are rabbeted as at 98 to conform with the slope and thicknessof flanges of member 80. Bottom plates (two in number) or retainerstrips 92 are secured to the underside of depending flanges 89 andprovide inclined surfaces 94 in supporting and bearing relationship withrespect to the inclined surface 84 of shoe member 88 The guide box thusfar described is attached to the platform 85 by means of cap screws 95(Fig. 11), or the like, extending up through normal clearance holes inthe platform from its underfor shoe 88, seen to best 11 side. and in thepreferred form of the invention the guide'box is aligned and centeredwith the underside of molding plate I2 by means of tapered dowel pins 99projecting downwardly into complementary apertures in the top surface ofinverted U member 08. In addition to the aforesaid dowel pins 90 (Figs.9 and 11), keys 8| are also preferably provided in combination with thesupporting structure for a side core 52, particularly where more thanone mold I4 and side core 52 are incorporated in a single castingmechanism. The keys I extend into keyways cut or otherwise formed in thetop surface of platform 06 and undersurface of retainer members 92 andserve, in combination with normal clearances provided in the taperedapertures receiving dowel pins 96 and clearance holes for bolts orscrews 95, to permit self adjustment of the guide boxes for shoes 80 tocompensate for dimensional changes between adjacent mold centers on theplate I2 arising out of expansion of this plate.

As in the case of side core the retainer strips 92 are centrally spacedfrom each other to provide an aperture and clearance for a depending ribor tang 98, integrally formed on the underside of shoe member 80 (Figs.7, 9, l0, l1, 12 and 14),

y as well as permit upward extension of replaceable stop blocks |00,secured to the underside of each retainer strip 92 and extendingupwardly into position to abut with the depending webs forming integrallugs |02 with the rear end or edge of shoe member 80. v

Relative movement between shoe member 00 and its guide box will causeits attached core 52 to move in a straight line path that is inclineddownwardly and inwardly towards, and on projection forms an acute anglewith, the vertical central axis of a cast piston (Fig. 9). To obtainthis rectilinear movement, the lugs I 02 of shoe member 80 are clevisand pin connected to the end of connecting rod |03 which extendsoutwardly from power cylinder |04. Power cylinder |04 is pivotallyattached at its rear end at I0| to the top surface of platform 86 (Fig.1).

The platform 86 is vertically movable beneath the molding plate I2 tocarry therewith each of the cores 52 and its associated guide box andcylinder |04. Platform 86 is substantially square, as viewed in theplane of its top surface, and is provided with integrally formed orattached depending guide brackets or wings |05 which slidingly engagewithin keyways |06 formed in four vertical columns |01. The columns |01'are secured at their bases to rigid and stationary portions of the basemember I0, and members associated therewith, and are vertically alignedby means of dowel pins |08 extending between the upper ends of thecolumns and the underside of bosses I |0 depending from the underside ofbase member I0 (Figs. 2, 7. 9 and 10). In the preferred construction aslight clearance is provided between the upper ends of columns |01 andthe under surfaces of bosses 0 (Fig. 9). This clearance permits growthof the columns without any binding and bowing action as a result oftemperature differentials accruing from casting operations.

A power cylinder II2, substantially centrally located beneath platform06, as viewed in Figs. 2 and '7, but towards the inner core supportingend, as viewed in Figs. 1, 9 and 10, is pivotally supported on a fixedtrunnion bracket I|4 at its lower end. and its connecting rod 5 isclevis and pin connected at IIS to the underside of platform 86. Thispower ycylinder installation 12 and connection to platform 00 providesmeans for vertical reciprocation of the cores 52 as will be described inmore detail in the operation of a complete casting cycle.

It will be understood from the description thus far of side cores 5| and52 that they are slidably mounted in guide boxes beneath the moldingplate I2. In this connection, inward movement of each side core 5|(Figs. 9 and 10) will be positively arrested by the vertical faces ofthe lugi 09 of each shoe 54 coming into abutment against the stop blocks00. This abutting relationship definitely and positively establishes theextent of movement of a core 5| in towards the vertical central axis ofa cast piston for each selected width of stop block 08. Outward movementof each of the cores 5| is also positively controlled by a ring member49, which is preferably a hardened and accurately ground steel annulusset into a recessed or shouldered aperture extending through the moldplate I2 (Figs. 7, 9 and 10) in axial alignment with the vertical axisof each mold cavity. It will be observed that the lower arcuate bodyportion oieach core 5| will abut against the surface of the bore of ring49 (Fig. 10) when the core is in its outer, or casting position.

Similarly, each core 52 is limited in its inward movement by stop blocks|00. Outward movement of core 52, however, when in a lowered position,is controlled by stop strips 45 (Figs. '1, 9, 10, 12 and 14) secured tothe rear or back ends of guide box members 88 and 92, which strips arespaced apart suiliciently to clear the lugs |02 of shoes 80, butotherwise arrest outward movement of the shoes as viewed in Figs. 9 andi0. The reason for the necessity of stop strips 45 in association withcores 52, as distinguished from the absence of such stop strips inassociation with cores 5|, is explained on the basis that cores 52 aremoved outwardly in their lowered position (Fig. 9), in which case theycould abut against the bore in ring 49, as a consequence of a particulardesign of core and the particular sequence of movements in an operatingcycle of the mechanism to be later described.

The central core member 53, for each pair of side cores 5I and 52, isvertically retractable.

This core has been illustrated as a single element (Figs. 7, :8, 9 and10), but it will be understood that it may be a sectional membercomposed of relatively movable lateral side sections and a centralsection. The central core 53 fills the space between the side cores 5|and 52, when they are in assembled position (Fig. 10) within the castingcavity of a mold I4, and completes the interior configuration of thepiston being cast. For this purpose the oppositely disposed sides orfaces H1 of central core 53, which abut against the interior faces ofcores 5| and 52 in assembled relationship (Fig. 8), are tapered towardsthe top of the core to aid in its assembly and extraction. Also, keys orprojecting rails H0 are provided on the faces ||1 for registry withcomplementary keyways I|9 in the side cores 5I and 52, to insurealignment and correct positioning of the three cores 5|, 52 and 53 inassembled relationship.

The core 53 is formed with an attached or integral flange |20 (Fig. 7)at its lower end, which ange has oppositely disposed integralprojections |2| that extend into keyways |22 formed in a pair ofvertical guide columns |23. The columns |23 are secured at their lowerends relative to the main base I0 and are provided with dowel ,actuationor activation Din connection plate 2 in the columns |01.

A vertically disposed rack bar |24 is connected to the lower end of eachcentral core 53 through a lost motion connection, as indicated by theextendedbolts |25. Each rack bar |24 meshes with a pinion |26 (Figs. '1and 9) keyed to a two-piece shaft |28. Shaft |28 is carried in journalbearings |29 secured in aligned relationship to a plate |30 within theinterior of base member |0'and stationarily fixed with respect thereto.Coupling flanges |3| on the adjacent ends of two-piece shaft |28 providefor lost motion rotation between the two sections of the shaft, and astriking plate |32 secured to an o-utboard end of one section of theshaft, as viewed in Figs. 2 and 7, provides a striking surface that maybe struck by mallet, or the like, to relieve an otherwise stickingcenter core 53, if the occasion arises.

to the underside of the molding same manner as described for Power meansfor operating the central cores 53 l is provided in the form ofahorizontal rack bar |35 (Figs. l, 2, 7, 9 and 15)#,suitably located andguided within a housing |36 extending across the front face of thecasting machine and within the base |0. Rack bar |35 meshes with pinion'teeth |31 cut into the shaft |28 (Figs. 7 and 9) and is reciprocated bymeans of a power cylinder |38. that is pivotally secured at its outerend at |39 (Fig. 1) to an interior portion of base |0, and has itsconnecting rod |40 attached to the rack bar |35.

The aforementioned vibrating members 48. which are preferably any wellknown type vof commercial pneumatic impulse vibrators, have beenillustrated as secured to the depending tangs10 and 98. It will beunderstood that, on of vibrators 48, a series of rapid vibratoryimpulses will be delivered to each of the side cores and 52 through themedium of their supporting shoes 54 and 80, respectively, with which thetangs and 98 are integrally formed. It should also be understood that asimilar vibrator could be attached to the center core 53, if desired, orthe mold sections I6 andI |1 could be vibrated in place of one or moreof the internal cores, or simultaneously therewith.

Gripper and conveyor mechanism The gripper mechanism, previouslyidentified in its entirety by the reference numeral |53, is reciprocallymounted for vertical movement towards and away from the molds |4. Themounting for the gripper mechanism consists of four vertical posts orshafts ends (Fig. 2) in a suitable bracket |53 attached to e. pad ormachined surface on the rear side of base 0. The upper ends of the fourposts |52 are tied together by means of a plate |54 and nuts |55,threaded on reduced end portions of posts 52, to form a rigid structure.i

Gripper mechanism |50 incorporates a cross head |56 (Figs. 1, 2 and 3)formed as an integral portion thereof. which is guided and supported onthe posts |52 for reciprocal movement with respect thereto. A powercylinder |51, preferably pneumatic because of the relatively longworking stroke required, is secured at its lower end (Figs. l and 2) toa bracket |58 attached to the main frame 0, and is similarly attached atits upper f end in vertical axial alignment by a bracket |60 carried bythe post-supporting bracket |53. Cylinder |51 is equipped with the usualpiston (not shown) and connecting rod |62 which is centrally attached bythreaded connection, or the like, to

|52 secured at their lower f 14 the cross head |66. An adjustable stopbolt |63 extendsY downwardly through the tie plate |64 into abuttingrelationship with the upper central surface of cross head |66 to limitthe upward travel thereof. J

It will be observed that control of pressure to |51 will cause crosshead gripper mechanism to vertically reciprocated from a. positionbetween mold sections 6 and |1 to an upper position governed by thesetting of adjustable stop bolt |63. In this connection, the lower limitof travel of cross head |56 is adjustable by means of filler or stopblocks (Figs.f 1, 2 and 3) embracing theposts |52 and replaceably heldin position through the mechanism of a cross bolt |68.

The cantilevered portion of' the gripper mechanism 50, which extendsforwardly (Fig. 2) from cross head |56 over the molds I4, serves tohouse a pair of clamping members axially aligned with each of thepistons produced in the molds I4. Referring to Figs. 1, 2 and 3, and inparticular to Figs. 4, 5 and 6, the specific construction of the gripperand clamping members will now be described. 'Ihe gripper mechanism |50is constructed in the general form of a partitioned boxlike structure|68 provided with longitudinal partition webs |69 forming channels ateither side thereof, and cross partition webs |10 extending upwardly aportion of the depth of webs |69 (Figs. 2 and 5). A bifurcated shiftermember |1|, there being one such shifter member for each mold |4, issupported upon the top surfaces of the cross partition webs |10 insliding assembly within the ychannels formed -by webs |69. An arcuatelyfaced jaw member |12 is disposed within each of the pockets or cavitiesformed by cross partitions |10, with its arcuate face `extending througha cut away portion of the partition webs |69 directly opposite eachpiston (Figs 4 and 5). Pins |13, secured as by welding within the jaws|12, extend upwardly into angularly disposed slots or grooves |14machined in the underside of the bifurcated shifters |1|, and relativelengthwise movement between the shifters |1| and the housing |68 acts toradially compress or expand the jaws |12 as controlled bythe angularslope of grooves |14. Since the housing |68 (Figs. 2 and 5) contains twobifurcated shifter members |1|, a dividing web |15 in each of the sidechannels of housing |68 supports a fixed pin |16 upon both ends of whichcoiled springs |11 are mounted for compressive engagement with the wallsof webs |15 and the end walls of cavities in the adjacent ends of thelegs of bifurcated members 1| (Fig. 5). The springs |11 tend to returnthe shifter members |1|, and associated jaws 12, to an expanded orreleased position. as viewed in Fig. 5.

Cover plates |18 (Figs. 2, 3, 4 and 6) are secured to and enclose thehousing |68. Upstanding brackets |19, formed integral with each of thecover plates |18, support a fulcrum pin on which is mounted a doubleended lever IBI. One end of each of the levers |8| is pin-slot connectedat |82 to a shifter member |1|, and the opposite end is pin-slotconnected at |83 to the movable connecting rod |84 extending from apneumatic. diaphragm type, pressure applying unit |85. The units |85 areeach supported by the cover plates |18 on brackets |86 mounted on spacedupstanding bosses |81 formed integral with `the cover plates (Figs. 2and 4). It will be understood that oscillation of the levers |8| abouttheir fulcrum shafts |80 by the application of ypressure to units willreact to shift the bifurcated members within the housing |68 to contractor expand the jaws |12.

In view of the extent of overhang of the gripper mechanism |50, it hasbeen found desirable to construct this portion of the mechanism fromlight metal such as aluminum alloy. It has also been found desirable toinstall a tapered or shouldered pin |9| (Figs. 2 and 8) on the undersideof the overhung end of housing |68. which registers with and bottoms ina socket |92 on the main base member i0, when gripper |50 is in itslower piston or casting grasping position. The described pin and socketfeature, in combination with the filler blocks |65, insure accuratehorizontal positioning of the gripper mechanism in registry with thepistons exposed by separation of mold sections I6 and Il.

Chute andcore chilling mechanisms The chute and core chilling mechanismsare to be seen to best advantage in Figs. 1, 2, 3, 10 and 15. Therein asuperstructure in the form of a table or platform is secured to the topsurface of base member I0 at the right end thereof as viewed in Fig. l.A pair of spaced parallel bearing blocks or journals 202 are secured tothe top surface of superstructure 20| and each supports a tubular shaftmember 203 in horizontal position. A cross bar 205 serves as a yoke torigidly tie the members 203 together, at their front'ends, and aninverted U-shaped bar 206 serves a similar purpose at the rear ends oftubular members 203 to thereby present a rigid structure. Intermediatethe tubular members 203 is a power cylinder 208 secured to the topsurface of superstructure 20| and 4having its connecting rod 2|0 (Fig.3) securely attached to the front yoke 205. From the structure thus fardescribed, it will be observed that forward movement of connecting rod2|0 will translate the tubular members 203 from the position they occupyin Fig. 3 to that disclosed in Fig. 10.

The rear ends of tubular members 203 are equipped with connecting elbows2|2, rigid piping 2|4, T-tting 2||, and flexible hose 2|5, all of whichform a communicating system with a liquid coolant or water` valve 2|6 ina supply line for the same. The front ends of tubular members 203 areeach provided with an adjustable spray or aspirating nozzle 2|8 incommunication with independent air valves 220, secured to the topsurface of platform 20|, through the medium of flexible hose connections2|9. Striker arms 222 i Fig. 2) adjustably secured to the end of tubularmembers 203. and reciprocal therewith, serve to strike operating buttons22| on the air valves 220, which action delivers air to the nozzles 2|8to draw liquid coolant from the interior of the tubular members 203 andspray the same on the cores 5|, 52 and 53, as illustrated in Fig. 10.The inverted U-shaped bar 206 may -be integrally formed with the strikerarms 222 (Fig. 2) and secured as a unit to the ends of tubular members203.

Secured to, and translatable with the above described core chillingsystem is a piston or casting receiving chute 200. Two inverted U-shapedmembers 224 and 225 supportthe chute 200 in the following manner. Member224 is secured, as by welding, to the underside or bottom of chute 200and its depending legs are fulcrumed or pivotally supported on a rod orbar 226 extending outwardly from and xed to the yoke bar 205. The secondinverted U-shaped member 225 is secured rigidly to yoke bar 205 andmerely acts-as a support for the rear end-of chute 200 when the latteris in a horizontal position, as viewed in full lines in Fig. 2. A bar221, secured as by welding to the outboard, overhung depending leg ofmember 225, is provided with an aperture at its opposite end throughwhich the fulcrum bar 226 extends, the bar 221 serving as an anti-spreadmember between the inverted U- member 225 and fulcrum bar 226.

It will be appreciated that translation of the core chilling nozzles 2I8into the position illustrated in Fig. `10 will carry the chute 200 intothe same lateral position with respect to a vertical plane passingthrough the axes of the molds I4. In this position chute 200 is directlyunder the gripper mechanism |50 to receive clamped pistons releasedtherefrom.

The chute 200 is also equipped with a projecting rod or iinger 230adjacent its open end 228. In the retracted position of chute 200 (Figs.1 and 3), the finger 230 extends outwardly into the path traversed by atripper element 232 adjustably mounted on the gripper mechanism |50.Lowering of the gripper mechanism, then, will tilt chute 200 about itsfulcrum pin 226 to discharge castings previously deposited thereinthrough release of the clamps |12 when the chute 200 was directly belowthe gripper mechanism (Fig. 10). It will be observed that the positionof fulcrum 226 is such that chute 200 will normally assume a horizontalposition with or without a piston or pistons in the chute. On positivetilting of chute 200, the pistons therein will slide out the openend/228 and enter a stationary conveying trough 234 (Fig. 2) leadingaway from the casting mechanism, and the chute will then return underits own weight and mounting to its normal horizontal position.

Power system Referring to Fig. 15, a diagrammatic view of the powersystem for the integrated piston molding mechanism will now bedescribed. In this view, only those elements of the coordinatedmechanism are illustrated that are essential to an understanding of thepower system.

The reference numeral 236 identities a iluld pressure, preferablyhydraulic, supply unit comprising the usual motor driven pump and tank.Fluid pressure line P and return line R, respectively, are in directconnection with the delivery side of the pump, and the return lines fromthe various hydraulically operated units employing the system in theirfunctional operation. Also. a valve controlled main or air line HP isprovided for supplying air under pressure to certain of the elementsincorporated in the mechanism.

Hydraulic cylinders 30 connected to mold sections and as well as towrist pin boss, borecontrolling cores 40, are connected in pairs to thehydraulic pressure supply 236 through a suitable four-way, singlesolenoid operated valve G. Energization of the solenoid G operates itsassociatedvalve to admit pressure to cylinders 30 to close the moldsections I6 and I1 and position cores 40 in casting position.De-energization of solenoid G, the valve being spring returned, admitshydraulic pressure to open the mold sections |6 and and withdraw thecores 40.

Hydraulic cylinder 12, connected to internal boss-forming core 5|, isconnected into the hydraulic pressure system 236 through double solenoidoperated, four-way valve A-B. Energization of solenoid A operates itsassociated valve to ati- 1 to admit pressure to cylinder 12 to move thecore 5| outwardly into position for a casting operation.

Hydraulic cylinder |04, connected to internal boss-forming core 52, isconnected into the hydraulic pressure supply 238 through double solenoidoperated, four-way valve C-D. Energization of solenoid C serves tooperate its associated valve to admit pressure to cylinder |04 to movethe core 52 inwardly towards the vertical axis of the piston being cast.De-energization of solenoid C and energization of solenoid D operatesthe valve to admit pressure to cylinder |04 to move core 52 outwardlyinto its casting position relative to mold section I1.

A second hydraulic cylinder ||2 is also associated with core 52 in thatit supplies the motive force for reciprocating this core vertically withrespect to its related mold |4. Cylinder H2 is connected through itsconnecting rod ||5 to platform 86 and is also connected into the powersupply 236 through the medium of single solenoid operated, four-wayvalve E. On energization of solenoid E, its associated valve is operatedto admit pressure to cylinder H2 to lower platform 86 and its supportedcore 52. The valve being spring returned, de-energization of solenoid Eadmits pressure to cylinder H2 to raise the core 52 into the castingcavity between mold sections I6 and l1.

Center core 53 is raised and lowered through control and supply ofhydraulic pressure to cylinder |38. This cylinder is connected through asingle solenoid operated four-way valve F. Energization of solenoid Foperates its associated valve to admit pressure to cylinder |38 to lowerthe core 53. De-energization of solenoid F operates the valve, which isspring returned, to admit pressure to the cylinder to raise the centercore 53 into the mold cavity.

Gripper mechanism |50 is reciprocated vertically by pneumatic cylinder|51. This cylinder is connected into the air supply line HP by means ofa four-way, single solenoid operated valve H. On energization ofsolenoid H. its associated valve admits air pressure to cylinder |51 tolower the gripper |50 into position between separated mold sections I6and l1. Deenergization of solenoid H, the valve being spring returned,admits pressure to cylinder |51 to raise the gripper |50.

Pneumatically operated units |85 which serve to operate casting clampingjaws |12 are connected into the air supply line HP through a fourway,double solenoid operated valve I-N. Energization of solenoid I serves tooperate its associated valve to admit pressure to units |85 toreciprocate shifter elements |1| to thereby diametrically compress jaws|12 into grasping contact with castings therebetween. De-energization ofsolenoid I and energlzation of solenoid N exhausts pressure from units|85 to release the jaws |12 and discharge castings grasped theretween.

Chute 200, and associated core chilling nozzles 2| 8, are simultaneouslyreciprocated into and out of position beneath gripper mechanism |50 byoperation of pneumatic cylinder 208, whichis connected into the airsupply line HP through the medium of four-way, single solenoid operatedCil '18 valve J. Energization of solenoid J causes its associated valveto admit pressurev to cylinder 208 to translate chute 200 and nozzles2|8 inwardly under the gripper mechanism |50. The opposite movement ofthe chute and nozzles occurs when the solenoid J is de-energized,y theJvalve being of the spring return type.

Internal core vibrator devices 48 are also connected into the air supplyline HP through a two-way, solenoid operated valve K. On energization ofsolenoid K the valve is operated to admit line pressure to the devices48. Deenergization of solenoid K interrupts delivery of pressure to thevibrator devices.

Similarly. a solenoid operated, two-way valve L is provided to controlnow of coolant from a suitable source, such as 'a valve 2|6 in a waterservice line, to spray nozzles 2| 8, solenoid L being energized topermit coolant ow and de-energized to interrupt the flow.

Although the power system has been described in terms of pneumatic andhydraulic fluid pressure instrumentalities, it will be apparent to thoseskilled in this art that a uniform iluid pressure system could beemployed throughout, without in any way detracting from the system ashereinabove described.

Wiring diagram Fig. 16 represents a wiring diagram that will now bedescribed in conjunction with the piston molding mechanism selected forpurposes of illustrating the invention. Fig. 16 will be described witnreference to the electrically energized elements appearing in Fig. l5,and the chart illustrated in Fig. 17.

In Fig. 16, X-l and X-2 represent conductors from any suitableelectrical power source, such as a volt, 60 cycle current supply, acrosswhich are connected the various electrical circuits that energize theelements incorporated in the molding mechanism.

The electrical control system includes a Vernier timer and a sequencetimer. Both timer ldevices are well known and, in the illustratedmechanism. a Vernier timer, Type 2805, and a sequence timer, Type 2411,were obtained from the Automatic Temperature Control Company ofPhiladelphia, Pennsylvania. It is to be understood that other knowntypes of timing mechanism may be substituted for the precise devicesherein selected forpurposes of illustrating the invention.

The Vernier timer mechanism incorporates a motor B-I, andelectromagnetic clutch X, at least two pairs of normally open contactsXC and CM|, a time interval selector, and mechanism coacting with theselector to effect momentary closure of contacts CM-l followingexpiration of a preselected time interval. The vernier timer is employedfor the specific purpose or providing a preselected time interval, byadjustment of the selector, for controlling the freezing or setting timeof the particular volume of molten metal cast in the molding mechanism,as well as initiating energization and operation of the sequence timeron expiration of the preselected time interval.

The sequence timer comprises a motor M-2 connected to a shaft .on whichare adjustably mounted a plurality of cams which sequentially close andopen an equal number of switch contacts T-l through T|| and a pair ofcontacts CM-2. The contacts CM-2 serve to complete a holding circuit forthe sequence timer motor M-2, and maintain this motor energized for onecomplete revolution of the cam shaft, and then automatically open themotor circuit, preparatory to a repeated or subsequent cycle ofoperation. During this complete revolution of the sequence timer camshaft. switch contacts T| through T|| are sequentially actuated, eachbeing held closed for a preset portion of a revolution of the cam shaftrepresenting a denlte timing interval.

Assuming that the fluid pressure system 236 lFig'. 15) and pneumaticpressure line HP are both activated to provide a source of availablehydraulic and pneumatic pressure; that the mold sections i6 and I1 areclosed or in casting position; and that the internal cores 52 and 53,and wrist pin cores 40, are in assembled relationship within the moldsI4, an operator of the mechanism initiates a casting cycle by firstfilling the molds with a molten metal charge of the desired alloycomposition. Both molds are preferably filled at the same time byemploying a two-spout ladle in pouring registry with adjacent grates 22.On completion of a metal pouring or mold charging operation, theoperator immediately depresses and closes master switch MS, and theoperation from that time forward is entirely automatic.

Closing of the switch MS completes the circuit for the vernier timerthrough conductor L-I, normally closed contacts of relay CR-2 andconductor L-2 across the main power supply lines X| and X-2 tosimultaneously energize the Vernier timer motor M-I and its clutchmechanism X, as well as light a red signal lamp. Contacts XCautomatically close in response to energization of the clutch X andprovide a holding circuit for motor M-I, clutch X and the signal light.Following the elapsed interval of time, as preselected, the contactsCM-I close momentarily and con- -nect the sequence timer motor M-2 andcontrol relay CR-2 across the power lines X-I and X-2. Shortly aftercontacts CM-i close, contacts XC are caused to open therebyde-energizing the electromagnetic clutch X, opening the circuit of motorM-I and the signal light, and resetting the Vernier timer for a new orsubsequent cycle of operation. It will be observed that the red signallamp is lighted for that period represented by the time required for themolten metal to solidify and actually acts as a visual danger signalagainst unwarranted opening of the molds, or the like.

The sequence timer now takes over in the following manner. Sequencetimer switch T-I closes and through conductor L-5 energizes controlrelay CRAL Energization of relay CR4 opens its two normally closedcontacts CR-4 in the circuit composed of conductor L-1, solenoid G andconductor L-B to de-energize solenoid G in the control circuit ofhydraulic cylinders 30, which serves to open the mold sections I6 andEnergization of relay CR/- also closes its open contacts CR-4 in thecircuit composed of conductor L-6 and open limit switch LS-FU, toprepare this circuit as a holding circuit for relay CRAI which holdingcircuit is completed by subsequent closing of limit switch LS-FU priorto time expiration of T-l, as hereinafter described.

Sequence timer contacts T-2, in point of time, are next closed.Automatic closing of switch T2, through conductors L-9 and L-IU, servesto energize solenoid H operating the Valve to pneumatic cylinder |51.Energization of solenoid H lowers connecting rod |62 and grippermechanism |50 into contact with the stop blocks |65, in which loweredposition the clamping jaws |12 are 20 diametrically disposed in open orexpanded condition on either side of the exposed cast pistons (Figs. 4and 9). Preferably, sequence timer contacts T| and T-2 will be set toclose simultaneously so that the gripper mechanism will have travelleddownwardly a substantial distance toward the stop blocks by the time themolds I4 assume an open position, which will avoid unnecessary delay inthe gripper mechanism reaching its lower position between the open moldsections |6 and I1.

Sequence timer contacts T-3 are next closed to energize control relayCR5 through conductor L-I l. Energization of relay CR-5 closes its twosets of contacts CR-5 in the circuit of conductors L-l3 and Ir-M toenergize solenoid F associated with the hydraulic cylinder |38 forcontrolling movement of center cores 53. On energization of solenoid Fthe center core actuating mechanism is operated to withdraw the cores 53vertically out of position between their complementary side cores 5| and52. Upon initial movement of the rack bar |35 in effecting center coreretraction or Withdrawal, the limit switch LS-FU is closed and completesthe holding circuit for control relay CRf-A, whereby the molds I4 cannotbe reclosed until the center cores 53 are moved back into castingposition between the side cores 5| and 52.' The limit switches LS-FU aresuitably attached to a portion of the main frame or base l0, in the pathof movement of each rack bar |35; and are manipulated thereby.

The duration or interval of sequence timer contacts T-3 (Fig. 17) isinitially selected and set for a suiilcient length of time to maintainrelay CR-5 energized, and its two pair of contacts Cit-5 in the circuitof conductor L|3 closed, so that solenoid F remains energized andcentral cores 53 withdrawn until the operative movements of side cores5| and 52 are completed, as will be hereinafter described in moredetail.

Sequence timer contacts T4 are next closed to effect energization ofcontrol relay CR-G through conductor L-I 5, after gripper mechanism |50has reached its lowered position. Control relay CR-B energizes andcloses its two normally open sets of contacts CR-B in the circuitcomposed of conductors )2r-I6, L|1 and solenoid I. Responsive toenergization of solenoid I, air pressure is admitted to pressureapplying units to reciprocate shifter elements |`l| to diametricallycollapse or close clamping jaws |12 to grip thecast pistonstherebetween.

Subsequent to gripping the exposed cast pistons, closing of sequencetimer contacts T-5 energizes control relay CR-'l in the circuitcompleted by conductor L-IS. Control relay CR-l has two normally opensets of contacts in the circuit of conductors L-20, L-2| and solenoid K,and on energization of relay CR/-l the open contacts are closed andsolenoid K is energized. Solenoid K, on energization, actuates itstwoway valve admitting pneumatic pressure to the vibrators 48 to vibratethe cores 5| and 52. The time or interval of vibration expires with thesequence setting of sequence timer contacts T-5 (Fig. 17).

Closing of sequence timer contacts T-6, next in point of elapsed time inthe operation of the sequence timer, energizes control relay CR-B in thecircuit of conductors L-22 and L-23. Energization of control relay CR-Bcloses its two normally open sets of contacts CRf-B in the circuit ofconductors L-24 and L-25 to energize solenoid C. .Solenoid C, onenergization, through its

